Real-Time Water Quality Deployment Report...2015/12/10 · Real-Time Water Quality Deployment...

Government of Newfoundland & Labrador Department of Environment and Conservation

Water Resources Management Division

St. John’s, NL, A1B 4J6 Canada

Real-Time Water Quality Deployment Report

Rattling Brook Network

December 10, 2015 to January 22, 2016

Real-Time Water Quality Deployment Report

Rattling Brook Network

2015-12-10 to 2016-01-22

1

General

Department of Environment and Conservation staff monitors the real-time web pages consistently.

Due to ice conditions, monitoring activities at Big Pond have been temporarily suspended. Monitoring is

expected to resume in the spring (as early as late April).

Hydrometric data included in this report is provisional and used only for illustrative purposes. Corrected and

finalized data may be retrieved from the Water Survey of Canada website (http://www.ec.gc.ca/rhc-wsc/)*.

Maintenance and Calibration of Instrument

As part of the Quality Assurance and Quality Control protocol (QAQC), an assessment of the reliability of

data recorded by an instrument is made at the beginning and end of the deployment period. The procedure is

based on the approach used by the United States Geological Survey.

o Upon deployment, a QA/QC Sonde is temporarily deployed in situ, adjacent to the Field Sonde.

Depending on the degree of difference between each parameter from the Field and QAQC

sondes a qualitative rank is assigned (See Table 1). The possible ranks, from most to least

desirable, are: Excellent, Good, Fair, Marginal, and Poor. A grab sample is also taken for

additional confirmation of conditions at deployment and to allow for future modelling studies.

o At the end of a deployment period, a freshly cleaned and calibrated QAQC Sonde is placed in

situ, adjacent to the Field Sonde. Values are compared between all parameters and differences

are ranked for placement in Table 1.

Table 1: Qualitative QAQC Ranking

Station Date Action Comparison Ranking

Temperature pH Conductivity Dissolved Oxygen Turbidity

Rattling Brook Big

Pond

December 11, 2015 Deployment Poor Fair Poor Excellent Excellent

January 21, 2016 Removal Excellent Excellent Excellent Good Good

Rattling Brook below

Bridge

December 11, 2015 Deployment Good Good Poor Good Excellent

January 21, 2016 Removal Good Excellent Excellent Fair Excellent

Rattling Brook below

Plant Discharge

December 10, 2015 Deployment Good Excellent Poor Poor Excellent

January 22, 2016 Removal Excellent Excellent Excellent Poor Excellent

QAQC rankings achieved during Deployment indicated potential problems. However, a significant

improvement in rankings at Removal gives a hint that disagreement between the Hydrolab DS5X (Field

Sonde) and YSI Exo2 (QAQC Sonde) at Deployment is responsible for unfavorable rankings. While the two

models usually agree to a large degree, the differences appear to be substantial enough that they skew

QAQC rankings. In the future, QAQC rankings will be performed with like models.

Rattling Brook Network, Long Harbour, Newfoundland and Labrador

*All hydrometric data is provisional and is subject to correction. Please consult Water survey of Canada for finalized data and

interpretation.

2

Data Interpretation

Temperature

Water Temperature is a major factor used to describe water quality. Temperature has major

implications on both the ecology and chemistry of a water body, governing processes such as the

metabolic rate of aquatic plants and animals and the degree of dissolved oxygen saturation.

Station Mean Median Min Max

Big Pond 0.44 0.31 -0.44 2.53

Below Bridge 0.57 0.37 -0.02 3.42

Below Plant Discharge 0.31 0.00 -0.22 3.71

By mid-deployment (~December 28th

) water temperature was near or occasionally below 0oC (supercooled)

at Bridge and Plant Stations. Big Pond station was marginally later to reach its low point, suggesting that ice

formation occurred somewhat later.

Approximately 8” of ice was found at Big Pond station during removal.



interpretation.

3

pH

pH is used to give an indication of the acidity or basicity of a solution. A pH of 7 denotes a

neutral solution while lower values are acidic and higher values are basic. Technically, the pH

of a solution indicates the availability of protons to react with molecules dissolved in water. Such

reactions can affect how molecules function chemically and metabolically.


Big Pond 6.51 6.54 6.26 6.64

Below Bridge 6.54 6.54 6.46 6.76

Below Plant Discharge 6.41 6.39 6.25 6.75

pH levels hovered near the top of the Site Specific Guidelines for the majority of the deployment period

(upper dashed line). Values were relatively stable throughout the timeframe owing to the season – pH does

not exhibit the drastic diurnal variation in the winter as it does in the spring, summer, and early fall.



interpretation.

4

Specific Conductivity

Conductivity relates to the ease of passing an electric charge – or resistance – through a

solution. Conductivity is highly influenced by the concentration of dissolved ions in solution:

distilled water has zero conductivity (infinite resistance) while salty solutions have high

conductivity (low resistance). Specific Conductivity is corrected to 25oC to allow comparison

across variable temperatures.


Big Pond 59.9 59.4 47.5 69.1

Below Bridge 57.6 58.2 52.3 64.2


Some indication of an rising trend is seen at Big Pond station, however, a sharp decline on January 12 is

likely related to snowmelt. An increasing trend is clearer at Bridge and Plant Discharge stations, possibly

due to the increased use of ice control measures in and around the Vale plant site.



interpretation.

5

Dissolved Oxygen

Dissolved oxygen is a metabolic requirement of aquatic plants and animals. The concentration of

oxygen in water depends on many factors, especially temperature – the saturation of oxygen in

water is inversely proportional to water temperature. Oxygen concentrations also tend to be

higher in flowing water compared to still, lake environments. Low oxygen concentrations can

give an indication of excessive decomposition of organic matter or the presence of oxidizing

materials.

Station variable Mean Median Min Max

Big Pond DO (mg/l) 14.02 13.81 13.25 15.93

Below Bridge DO (mg/l) 14.06 14.07 13.01 14.68

Below Plant Discharge DO (mg/l) 13.49 13.48 12.30 14.17

Near the end of the deployment period dissolved oxygen concentrations have likely reached their annual

maxima as a result of freezing conditions at all stations. Concentrations are expected to decline towards the

end of February and March as water temperatures begin to rise into the spring.



interpretation.

6

Turbidity

Turbidity is typically caused by fine suspended solids such as silt, clay, or organic material.

Consistently high levels of turbidity tend to block sunlight penetration into a waterbody,

discouraging plant growth. High turbidity can also damage the delicate respiratory organs of

aquatic animals and cover spawning areas.


Big Pond 3.4 3.4 1.6 14.4

Below Bridge 1.0 0.0 0.0 223.8


As soils are frozen and become stable and ground surfaces are blanketed by snow, turbidity levels tend to

fall to annual minima. Contrary to expectations, turbidity levels were highest at Big Pond station and

hovered near 3.4 NTU for the majority of the deployment. This low level of turbidity could be the result of

seasonal mixing within Big Pond as stratification has broken down and water is able to turn over to a greater

degree.



interpretation.

7


8

Appendix

Prepared by:

Ryan Pugh

Department of Environment and Conservation

Water Resources Management Division

Phone: 709.729.1681

Fax: 709.729.3020

Real-Time Water Quality Deployment Report...2015/12/10 · Real-Time Water Quality Deployment...

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